The U.S. Department of Justice recently reevaluated its prosecutors’ pretrial disclosure practices in light of its highly-publicized discovery failure in the prosecution of U.S. Senator Ted Stevens. Based on its working group’s recommendations, the Department undertook several new initiatives, chief among them being a commitment to better training regarding discovery obligations and how to comply with them. This essay explores an alternative approach to improving prosecutorial disclosure practices – namely, learning from discovery mistakes. It appears that few, if any, federal or state prosecutors’ offices seek to improve their institutional practices by systematically studying cases in which prosecutors failed to disclose evidence or other information to the defense as required by law. This essay considers why. It identifies, and calls into question, several reasons that prosecutors might offer for their reluctance to analyze individual prosecutors’ lapses. It also notes various institutional challenges that prosecutors’ offices might encounter in seeking to learn from their prosecutors’ mistakes, but concludes that it is worth making the attempt.